export function formatDateTime(input) {
  if (!input) return '无'
  const date = input instanceof Date ? input : new Date(input)
  if (isNaN(date.getTime())) return '无效时间'
  const y = date.getFullYear()
  const m = String(date.getMonth() + 1).padStart(2, '0')
  const d = String(date.getDate()).padStart(2, '0')
  const hh = String(date.getHours()).padStart(2, '0')
  const mm = String(date.getMinutes()).padStart(2, '0')
  const ss = String(date.getSeconds()).padStart(2, '0')
  return `${y}-${m}-${d} ${hh}:${mm}:${ss}`
}